Figure 1.

Functionality of TED correlates with its ability to compete for TED-dependent translation in trans. (A) TED deletion derivatives have a lower functionality. RNAs containing the Ω-fragment of the TMV as leader (5), the cat coding region and different TED derivatives were translated in wheat germ. The amount of CAT synthesised from these RNAs was determined after 100 min. The stimulation of CAT synthesis by the different TED derivatives is given as compared to the non-functional TED_(688–753) (1). (B) In cis functionality of TED derivatives correlates with efficiency of competition in trans. 0.5 pmol RNA-R655TED, consisting of a 19 nt polylinker sequence (5), cat and TED, was translated in a 12.5 µl reaction mixture during 120 min in the presence of 0–70 pmol of different competitor RNAs. The amount of CAT is given as a percentage of the amount in the absence of competitor. (C) TED derivatives compete for TED-dependent translation at the level of translational efficiency. RNA-R655TED was translated in wheat germ in the presence of a 5-fold molar excess (open bars) and a 70-fold molar excess (black bars) of different competitor RNAs. The CAT synthesis was determined at seven time points and from the resulting protein accumulation profile the translational efficiency of the TED-containing RNA was determined. The values for the translational efficiency are given as percentages of the values in the absence of competitor.